The sleeper fish Eleotris oxycephala is present in freshwater streams and estuaries from tropical to temperate zones. The current discovery of a person of this species a lot additional north than beforehand recorded means that the vary of this species could also be increasing in Japan.
In a examine revealed this month, researchers from the University of Tsukuba report the invention of a juvenile Eleotris oxycephala in Akita Prefecture in northern Japan. Eleotris oxycephala is an amphidromous fish, which means that the fish are born in freshwater streams or estuaries, drift out to the ocean as larvae, after which migrate again to freshwater programs to reside out their juvenile and grownup phases. In Japan, Eleotris oxycephala has beforehand been discovered from the Osumi Islands within the south to Ishikawa and Fukushima prefectures within the north. The current discovering of a juvenile within the Yoneshiro River system in Akita Prefecture extends the recognized distribution of the species roughly 500 km northeast.
“We think that the juvenile most likely reached the Yoneshiro River from the south via larval dispersal in the Tsushima Current,” says lead writer of the examine, Professor Yoshiaki Tsuda. “No adults were found, and it is unlikely that this species could mature and reproduce in this river because the winter water temperatures are too cold.”
The seasonally variable Tsushima Current runs in a northeasterly route alongside the Sea of Japan coast, between Japan and Korea/China, and helps to disperse many fish species.
“Reports of Eleotris oxycephala have been increasing along the Sea of Japan coast since 2000,” explains Professor Tsuda. “This can be partly explained by an increase in the number of fish surveys being conducted, but warming water temperatures could also be playing a role.”
Poleward vary shifts related to growing temperatures have been noticed for a lot of species globally. Temperatures within the Sea of Japan have elevated by about 1.5 levels Celsius within the final hundred years and are persevering with to rise. In Japan, a lot of southern fishes have already proven northward vary extensions and the potential northward motion of Eleotris oxycephala ought to be monitored.
Uchu Yamakawa et al, Northernmost file of Eleotris oxycephala (Gobioidei: Eleotridae) primarily based on a juvenile specimen from Akita Prefecture in northern Japan: vary extension alongside the Sea of Japan shoreline,Biogeography (2021). DOI: 10.11358/biogeo.23.6
University of Tsukuba
Recent discovery hints at northward shift in fish distribution (2021, October 7)
retrieved 7 October 2021
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